PROJECT SUMMARY: Analytical Core Polychlorinated biphenyls (PCBs) are important Superfund chemicals that are known human carcinogens also associated with neurological and metabolic disruption. The Analytical Core (AC) provides analytical services to the ISRP to facilitate high-quality research on PCBs, including data, standard operating procedures, and peer- reviewed publications that are standardized, efficient, and comparable across all ISRP matrices and projects. The AC provides instrumentation and facilities, expert staff, training, data sharing platforms, and support for method development. The AC will continue to accomplish these activities through five Specific Aims: Aim 1. Maintain analytical quality assurance (QA) standards and protocols. Accurate, precise, representative, reproducible, and comparable sample analysis is absolutely essential for all five ISRP projects and is a key AC objective. The exceptional rigor of the QA protocol for PCB analysis provides a critical foundation for discoveries by the ISRP projects. Aim 2. Facilitate high-throughput analysis in complex biotic and abiotic matrices. The AC supports ISRP projects by extracting and analyzing samples for all 209 PCBs and 72 OH- PCBs as MeO-PCBs in complex matrices, including: air samples collected on quartz filters, XAD resin, and polyurethane foam; sediment, water, and pore water samples; human serum; laboratory animal tissues; plant tissues; soils; microbial cultures; and polymers, paints, and pigments. To support new research directions within the ISRP, we will expand our capabilities to include analyses of food matrices and the ability to quantify all 837 possible mono-hydroxylated PCBs. Aim 3. Provide prioritized training and access to AC facilities. The AC, in collaboration with the Research Experience and Training Coordination Core, provides prioritized, standardized training in AC facilities and methods to graduate student and postdoc trainees, faculty, and staff from all ISRP projects. Trainees also receive assistance in method development and use of instrumentation. Aim 4. Support method development for complex matrices. The AC, in collaboration with ISRP projects, will continue to develop, maintain, and update methods for high-throughput PCB and OH-PCB extraction and analysis in biotic and abiotic samples. Separate but comparable methods are maintained across matrices to facilitate integrated data analysis. Aim 5. Maintain analytical infrastructure. The AC maintains critical infrastructure, including high-use analytical instruments, a sample database, and archives such as standard solutions, samples, and sample extracts. The AC, in collaboration with the Data Management and Analysis Core, will provide oversight to make data findable, accessible, interoperable, and reusable (FAIR) by ISRP investigators. Overall, the AC is a fully-integrated support core that assists ISRP projects to meet all four SRP mandates requiring methods for identifying human health hazards of superfund chemicals, detection, assessment of exposure risk, and remediation.